Some interpretations of this verse, and others like it, both in the Old and New Testaments, don’t take this literally, but say that throughout scripture, the sun and the moon and the stars are used symbolically to represent the rulers of this world. As the sun and the moon and the stars give light and guidance to the world, so our rulers are supposed to guide us. The sun and the moon and the stars falling, or turning to blood, in this sense, might be speaking of the fall of kings, kingdoms, and nations.